1. Field of Invention
In some athletic games, such as golf, a playing device, such as a golf ball, is temporarily lost, so that one or more players must devote time to searching. Sometimes a golf ball is not found, thus adding to the expense of the sport. Golf balls are not extremely expensive. Few golfers care to spend large amounts for money for a retrieval system involving golf balls costing significantly more than conventional golf balls. The method and apparatus are also useful for searching for and retrieving creatures, experimentally launched model airplanes, or other items which might be temporarily lost.
2. Prior Art
Horchler U.S. Pat. No. 3,782,730 uses a magnetically actuated switch to turn on or off a radio oscillator at the core of the golf ball, whose radio signal can be monitored by the player whenever the ball is temporarily lost.
Engimeier U.S. Pat. No. 5,423,439 employs a rechargeable battery and a system for electromagnetically transmitting energy to the battery charger of a Horchler type of golf ball.
Little U.S. Pat. No. 5,626,531 employs a capacitance system which tags such ball whenever activated by the radiation from by the radiation from a Horchler-type of target-seeking monitor.
Kroll et al U.S. Pat. No. 5,662,534 also uses a monitor sending out a series of pulses of radio beams, and analyzing the reflected radio waves. In Kroll et al, the golf ball feature a generic reflector of such radio beams.
Valintino U.S. Pat. No. 5,132,622 employs a golf ball having a metal center and the combination of a metal detector and target-seeking scoop to retrieve a lost golf ball.
Digital pulses of infra-red laser beams having a wavelength of 1310 nm are suitable for optical wireless systems over distances of a few kilometers, according to Heatley et al, IWWW Communications magazine, December 1998, pp 72-82.
Although radar systems have been helpful in locating gigantic targets, their effectiveness with items as small as a golf ball have been unsatisfactory. Moreover, a golf ball containing significant mass of transmitter, tagging components, capacitors, etc. has flight characteristics which are dysfunctional. Around the world, the number of golfers, and the number of golf balls manufactured, has continued to climb, thus accentuating the long-standing-need for a system for retrieving a temporarily lost ball. Similar problems occur with croquet balls and other sports paraphernalia. Model airplanes and creatures are sometimes temporarily lost, and are retrievable using the apparatus and method of the present invention.
In accordance with the present invention, a searcher utilizes a monitoring device emitting a laser beam of a particular wavelength, and the reflected light attributable to such laser beam is analyzed for identifying the target zone providing the most intense reflection, inasmuch as the item to be retrieved has been modified to preferentially reflect light when such laser beam reaches it Earphones or a meter, or other appropriate indicating means, can be used in monitoring for the targeted zone having the temporarily lost golf ball or the like. The flight characteristics of the golf ball of the present invention are substantially identical to those of a conventional golf ball, because the ball of the present invention differs from a conventional golf ball only by reason of having on its exterior surface, an appropriate hologram comprising components particularly reflecting a laser beam of predetermined wavelength. In the process of the present invention, a conventional golf ball or [other athletic paraphernalia such as a croquet ball or a model airplane or a creature] is cleaned and then is labeled [usually coated] with the material imparting the selective reflectivity for the laser beam of the preselected wavelength. The term xe2x80x9chologramxe2x80x9d is employed for certain types of such selected reflectivity. After the athletic paraphernalia has been thus treated, a sufficient amount of the selected material remains on the item to selectively respond to the laser beam having the pre-selected wavelength. It has been estimated that even after a holgramized ball has been played for 180 holes, or ten rounds of golf, it might retain effective amounts of the hologram material. Some golf balls have a plurality of approximately hemispherical depressions which retain the selective reflectivity even when some of the outermost portions of the ball are dirty. Because the cost of coating the ball with the selective material is not prohibitive, a golf course can repeat the treatment for a ball after even 9 holes of use. Occasionally a freshly hologramized ball becomes excessively dirty and is not adequately responsive to the target-seeking monitoring system featuring the laser beam of predetermined wavelength. However, the dirt accumulated during normal golf games does not impair the effectiveness of the retrieval system of the present invention. The plastic film deposited in a depression of the golf ball can be molded to impart a hologram of the type responsive to the laser beam reaching such molded ridges having angle and spacing appropriate for the selected wavelength.